789 lines
20 KiB
C
789 lines
20 KiB
C
/*
|
|
* Copyright IBM Corp. 2007, 2011
|
|
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
|
|
*/
|
|
|
|
#include <linux/sched.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/gfp.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/swap.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/rcupdate.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/swapops.h>
|
|
#include <linux/sysctl.h>
|
|
#include <linux/ksm.h>
|
|
#include <linux/mman.h>
|
|
|
|
#include <asm/pgtable.h>
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/tlb.h>
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/mmu_context.h>
|
|
|
|
static inline pte_t ptep_flush_direct(struct mm_struct *mm,
|
|
unsigned long addr, pte_t *ptep)
|
|
{
|
|
pte_t old;
|
|
|
|
old = *ptep;
|
|
if (unlikely(pte_val(old) & _PAGE_INVALID))
|
|
return old;
|
|
atomic_inc(&mm->context.flush_count);
|
|
if (MACHINE_HAS_TLB_LC &&
|
|
cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
|
|
__ptep_ipte(addr, ptep, IPTE_LOCAL);
|
|
else
|
|
__ptep_ipte(addr, ptep, IPTE_GLOBAL);
|
|
atomic_dec(&mm->context.flush_count);
|
|
return old;
|
|
}
|
|
|
|
static inline pte_t ptep_flush_lazy(struct mm_struct *mm,
|
|
unsigned long addr, pte_t *ptep)
|
|
{
|
|
pte_t old;
|
|
|
|
old = *ptep;
|
|
if (unlikely(pte_val(old) & _PAGE_INVALID))
|
|
return old;
|
|
atomic_inc(&mm->context.flush_count);
|
|
if (cpumask_equal(&mm->context.cpu_attach_mask,
|
|
cpumask_of(smp_processor_id()))) {
|
|
pte_val(*ptep) |= _PAGE_INVALID;
|
|
mm->context.flush_mm = 1;
|
|
} else
|
|
__ptep_ipte(addr, ptep, IPTE_GLOBAL);
|
|
atomic_dec(&mm->context.flush_count);
|
|
return old;
|
|
}
|
|
|
|
static inline pgste_t pgste_get_lock(pte_t *ptep)
|
|
{
|
|
unsigned long new = 0;
|
|
#ifdef CONFIG_PGSTE
|
|
unsigned long old;
|
|
|
|
asm(
|
|
" lg %0,%2\n"
|
|
"0: lgr %1,%0\n"
|
|
" nihh %0,0xff7f\n" /* clear PCL bit in old */
|
|
" oihh %1,0x0080\n" /* set PCL bit in new */
|
|
" csg %0,%1,%2\n"
|
|
" jl 0b\n"
|
|
: "=&d" (old), "=&d" (new), "=Q" (ptep[PTRS_PER_PTE])
|
|
: "Q" (ptep[PTRS_PER_PTE]) : "cc", "memory");
|
|
#endif
|
|
return __pgste(new);
|
|
}
|
|
|
|
static inline void pgste_set_unlock(pte_t *ptep, pgste_t pgste)
|
|
{
|
|
#ifdef CONFIG_PGSTE
|
|
asm(
|
|
" nihh %1,0xff7f\n" /* clear PCL bit */
|
|
" stg %1,%0\n"
|
|
: "=Q" (ptep[PTRS_PER_PTE])
|
|
: "d" (pgste_val(pgste)), "Q" (ptep[PTRS_PER_PTE])
|
|
: "cc", "memory");
|
|
#endif
|
|
}
|
|
|
|
static inline pgste_t pgste_get(pte_t *ptep)
|
|
{
|
|
unsigned long pgste = 0;
|
|
#ifdef CONFIG_PGSTE
|
|
pgste = *(unsigned long *)(ptep + PTRS_PER_PTE);
|
|
#endif
|
|
return __pgste(pgste);
|
|
}
|
|
|
|
static inline void pgste_set(pte_t *ptep, pgste_t pgste)
|
|
{
|
|
#ifdef CONFIG_PGSTE
|
|
*(pgste_t *)(ptep + PTRS_PER_PTE) = pgste;
|
|
#endif
|
|
}
|
|
|
|
static inline pgste_t pgste_update_all(pte_t pte, pgste_t pgste,
|
|
struct mm_struct *mm)
|
|
{
|
|
#ifdef CONFIG_PGSTE
|
|
unsigned long address, bits, skey;
|
|
|
|
if (!mm_use_skey(mm) || pte_val(pte) & _PAGE_INVALID)
|
|
return pgste;
|
|
address = pte_val(pte) & PAGE_MASK;
|
|
skey = (unsigned long) page_get_storage_key(address);
|
|
bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
|
|
/* Transfer page changed & referenced bit to guest bits in pgste */
|
|
pgste_val(pgste) |= bits << 48; /* GR bit & GC bit */
|
|
/* Copy page access key and fetch protection bit to pgste */
|
|
pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT);
|
|
pgste_val(pgste) |= (skey & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
|
|
#endif
|
|
return pgste;
|
|
|
|
}
|
|
|
|
static inline void pgste_set_key(pte_t *ptep, pgste_t pgste, pte_t entry,
|
|
struct mm_struct *mm)
|
|
{
|
|
#ifdef CONFIG_PGSTE
|
|
unsigned long address;
|
|
unsigned long nkey;
|
|
|
|
if (!mm_use_skey(mm) || pte_val(entry) & _PAGE_INVALID)
|
|
return;
|
|
VM_BUG_ON(!(pte_val(*ptep) & _PAGE_INVALID));
|
|
address = pte_val(entry) & PAGE_MASK;
|
|
/*
|
|
* Set page access key and fetch protection bit from pgste.
|
|
* The guest C/R information is still in the PGSTE, set real
|
|
* key C/R to 0.
|
|
*/
|
|
nkey = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56;
|
|
nkey |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48;
|
|
page_set_storage_key(address, nkey, 0);
|
|
#endif
|
|
}
|
|
|
|
static inline pgste_t pgste_set_pte(pte_t *ptep, pgste_t pgste, pte_t entry)
|
|
{
|
|
#ifdef CONFIG_PGSTE
|
|
if ((pte_val(entry) & _PAGE_PRESENT) &&
|
|
(pte_val(entry) & _PAGE_WRITE) &&
|
|
!(pte_val(entry) & _PAGE_INVALID)) {
|
|
if (!MACHINE_HAS_ESOP) {
|
|
/*
|
|
* Without enhanced suppression-on-protection force
|
|
* the dirty bit on for all writable ptes.
|
|
*/
|
|
pte_val(entry) |= _PAGE_DIRTY;
|
|
pte_val(entry) &= ~_PAGE_PROTECT;
|
|
}
|
|
if (!(pte_val(entry) & _PAGE_PROTECT))
|
|
/* This pte allows write access, set user-dirty */
|
|
pgste_val(pgste) |= PGSTE_UC_BIT;
|
|
}
|
|
#endif
|
|
*ptep = entry;
|
|
return pgste;
|
|
}
|
|
|
|
static inline pgste_t pgste_pte_notify(struct mm_struct *mm,
|
|
unsigned long addr,
|
|
pte_t *ptep, pgste_t pgste)
|
|
{
|
|
#ifdef CONFIG_PGSTE
|
|
unsigned long bits;
|
|
|
|
bits = pgste_val(pgste) & (PGSTE_IN_BIT | PGSTE_VSIE_BIT);
|
|
if (bits) {
|
|
pgste_val(pgste) ^= bits;
|
|
ptep_notify(mm, addr, ptep, bits);
|
|
}
|
|
#endif
|
|
return pgste;
|
|
}
|
|
|
|
static inline pgste_t ptep_xchg_start(struct mm_struct *mm,
|
|
unsigned long addr, pte_t *ptep)
|
|
{
|
|
pgste_t pgste = __pgste(0);
|
|
|
|
if (mm_has_pgste(mm)) {
|
|
pgste = pgste_get_lock(ptep);
|
|
pgste = pgste_pte_notify(mm, addr, ptep, pgste);
|
|
}
|
|
return pgste;
|
|
}
|
|
|
|
static inline pte_t ptep_xchg_commit(struct mm_struct *mm,
|
|
unsigned long addr, pte_t *ptep,
|
|
pgste_t pgste, pte_t old, pte_t new)
|
|
{
|
|
if (mm_has_pgste(mm)) {
|
|
if (pte_val(old) & _PAGE_INVALID)
|
|
pgste_set_key(ptep, pgste, new, mm);
|
|
if (pte_val(new) & _PAGE_INVALID) {
|
|
pgste = pgste_update_all(old, pgste, mm);
|
|
if ((pgste_val(pgste) & _PGSTE_GPS_USAGE_MASK) ==
|
|
_PGSTE_GPS_USAGE_UNUSED)
|
|
pte_val(old) |= _PAGE_UNUSED;
|
|
}
|
|
pgste = pgste_set_pte(ptep, pgste, new);
|
|
pgste_set_unlock(ptep, pgste);
|
|
} else {
|
|
*ptep = new;
|
|
}
|
|
return old;
|
|
}
|
|
|
|
pte_t ptep_xchg_direct(struct mm_struct *mm, unsigned long addr,
|
|
pte_t *ptep, pte_t new)
|
|
{
|
|
pgste_t pgste;
|
|
pte_t old;
|
|
|
|
preempt_disable();
|
|
pgste = ptep_xchg_start(mm, addr, ptep);
|
|
old = ptep_flush_direct(mm, addr, ptep);
|
|
old = ptep_xchg_commit(mm, addr, ptep, pgste, old, new);
|
|
preempt_enable();
|
|
return old;
|
|
}
|
|
EXPORT_SYMBOL(ptep_xchg_direct);
|
|
|
|
pte_t ptep_xchg_lazy(struct mm_struct *mm, unsigned long addr,
|
|
pte_t *ptep, pte_t new)
|
|
{
|
|
pgste_t pgste;
|
|
pte_t old;
|
|
|
|
preempt_disable();
|
|
pgste = ptep_xchg_start(mm, addr, ptep);
|
|
old = ptep_flush_lazy(mm, addr, ptep);
|
|
old = ptep_xchg_commit(mm, addr, ptep, pgste, old, new);
|
|
preempt_enable();
|
|
return old;
|
|
}
|
|
EXPORT_SYMBOL(ptep_xchg_lazy);
|
|
|
|
pte_t ptep_modify_prot_start(struct mm_struct *mm, unsigned long addr,
|
|
pte_t *ptep)
|
|
{
|
|
pgste_t pgste;
|
|
pte_t old;
|
|
|
|
preempt_disable();
|
|
pgste = ptep_xchg_start(mm, addr, ptep);
|
|
old = ptep_flush_lazy(mm, addr, ptep);
|
|
if (mm_has_pgste(mm)) {
|
|
pgste = pgste_update_all(old, pgste, mm);
|
|
pgste_set(ptep, pgste);
|
|
}
|
|
return old;
|
|
}
|
|
EXPORT_SYMBOL(ptep_modify_prot_start);
|
|
|
|
void ptep_modify_prot_commit(struct mm_struct *mm, unsigned long addr,
|
|
pte_t *ptep, pte_t pte)
|
|
{
|
|
pgste_t pgste;
|
|
|
|
if (mm_has_pgste(mm)) {
|
|
pgste = pgste_get(ptep);
|
|
pgste_set_key(ptep, pgste, pte, mm);
|
|
pgste = pgste_set_pte(ptep, pgste, pte);
|
|
pgste_set_unlock(ptep, pgste);
|
|
} else {
|
|
*ptep = pte;
|
|
}
|
|
preempt_enable();
|
|
}
|
|
EXPORT_SYMBOL(ptep_modify_prot_commit);
|
|
|
|
static inline pmd_t pmdp_flush_direct(struct mm_struct *mm,
|
|
unsigned long addr, pmd_t *pmdp)
|
|
{
|
|
pmd_t old;
|
|
|
|
old = *pmdp;
|
|
if (pmd_val(old) & _SEGMENT_ENTRY_INVALID)
|
|
return old;
|
|
if (!MACHINE_HAS_IDTE) {
|
|
__pmdp_csp(pmdp);
|
|
return old;
|
|
}
|
|
atomic_inc(&mm->context.flush_count);
|
|
if (MACHINE_HAS_TLB_LC &&
|
|
cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
|
|
__pmdp_idte(addr, pmdp, IDTE_LOCAL);
|
|
else
|
|
__pmdp_idte(addr, pmdp, IDTE_GLOBAL);
|
|
atomic_dec(&mm->context.flush_count);
|
|
return old;
|
|
}
|
|
|
|
static inline pmd_t pmdp_flush_lazy(struct mm_struct *mm,
|
|
unsigned long addr, pmd_t *pmdp)
|
|
{
|
|
pmd_t old;
|
|
|
|
old = *pmdp;
|
|
if (pmd_val(old) & _SEGMENT_ENTRY_INVALID)
|
|
return old;
|
|
atomic_inc(&mm->context.flush_count);
|
|
if (cpumask_equal(&mm->context.cpu_attach_mask,
|
|
cpumask_of(smp_processor_id()))) {
|
|
pmd_val(*pmdp) |= _SEGMENT_ENTRY_INVALID;
|
|
mm->context.flush_mm = 1;
|
|
} else if (MACHINE_HAS_IDTE)
|
|
__pmdp_idte(addr, pmdp, IDTE_GLOBAL);
|
|
else
|
|
__pmdp_csp(pmdp);
|
|
atomic_dec(&mm->context.flush_count);
|
|
return old;
|
|
}
|
|
|
|
pmd_t pmdp_xchg_direct(struct mm_struct *mm, unsigned long addr,
|
|
pmd_t *pmdp, pmd_t new)
|
|
{
|
|
pmd_t old;
|
|
|
|
preempt_disable();
|
|
old = pmdp_flush_direct(mm, addr, pmdp);
|
|
*pmdp = new;
|
|
preempt_enable();
|
|
return old;
|
|
}
|
|
EXPORT_SYMBOL(pmdp_xchg_direct);
|
|
|
|
pmd_t pmdp_xchg_lazy(struct mm_struct *mm, unsigned long addr,
|
|
pmd_t *pmdp, pmd_t new)
|
|
{
|
|
pmd_t old;
|
|
|
|
preempt_disable();
|
|
old = pmdp_flush_lazy(mm, addr, pmdp);
|
|
*pmdp = new;
|
|
preempt_enable();
|
|
return old;
|
|
}
|
|
EXPORT_SYMBOL(pmdp_xchg_lazy);
|
|
|
|
static inline pud_t pudp_flush_direct(struct mm_struct *mm,
|
|
unsigned long addr, pud_t *pudp)
|
|
{
|
|
pud_t old;
|
|
|
|
old = *pudp;
|
|
if (pud_val(old) & _REGION_ENTRY_INVALID)
|
|
return old;
|
|
if (!MACHINE_HAS_IDTE) {
|
|
/*
|
|
* Invalid bit position is the same for pmd and pud, so we can
|
|
* re-use _pmd_csp() here
|
|
*/
|
|
__pmdp_csp((pmd_t *) pudp);
|
|
return old;
|
|
}
|
|
atomic_inc(&mm->context.flush_count);
|
|
if (MACHINE_HAS_TLB_LC &&
|
|
cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
|
|
__pudp_idte(addr, pudp, IDTE_LOCAL);
|
|
else
|
|
__pudp_idte(addr, pudp, IDTE_GLOBAL);
|
|
atomic_dec(&mm->context.flush_count);
|
|
return old;
|
|
}
|
|
|
|
pud_t pudp_xchg_direct(struct mm_struct *mm, unsigned long addr,
|
|
pud_t *pudp, pud_t new)
|
|
{
|
|
pud_t old;
|
|
|
|
preempt_disable();
|
|
old = pudp_flush_direct(mm, addr, pudp);
|
|
*pudp = new;
|
|
preempt_enable();
|
|
return old;
|
|
}
|
|
EXPORT_SYMBOL(pudp_xchg_direct);
|
|
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
|
|
pgtable_t pgtable)
|
|
{
|
|
struct list_head *lh = (struct list_head *) pgtable;
|
|
|
|
assert_spin_locked(pmd_lockptr(mm, pmdp));
|
|
|
|
/* FIFO */
|
|
if (!pmd_huge_pte(mm, pmdp))
|
|
INIT_LIST_HEAD(lh);
|
|
else
|
|
list_add(lh, (struct list_head *) pmd_huge_pte(mm, pmdp));
|
|
pmd_huge_pte(mm, pmdp) = pgtable;
|
|
}
|
|
|
|
pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
|
|
{
|
|
struct list_head *lh;
|
|
pgtable_t pgtable;
|
|
pte_t *ptep;
|
|
|
|
assert_spin_locked(pmd_lockptr(mm, pmdp));
|
|
|
|
/* FIFO */
|
|
pgtable = pmd_huge_pte(mm, pmdp);
|
|
lh = (struct list_head *) pgtable;
|
|
if (list_empty(lh))
|
|
pmd_huge_pte(mm, pmdp) = NULL;
|
|
else {
|
|
pmd_huge_pte(mm, pmdp) = (pgtable_t) lh->next;
|
|
list_del(lh);
|
|
}
|
|
ptep = (pte_t *) pgtable;
|
|
pte_val(*ptep) = _PAGE_INVALID;
|
|
ptep++;
|
|
pte_val(*ptep) = _PAGE_INVALID;
|
|
return pgtable;
|
|
}
|
|
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
|
|
|
|
#ifdef CONFIG_PGSTE
|
|
void ptep_set_pte_at(struct mm_struct *mm, unsigned long addr,
|
|
pte_t *ptep, pte_t entry)
|
|
{
|
|
pgste_t pgste;
|
|
|
|
/* the mm_has_pgste() check is done in set_pte_at() */
|
|
preempt_disable();
|
|
pgste = pgste_get_lock(ptep);
|
|
pgste_val(pgste) &= ~_PGSTE_GPS_ZERO;
|
|
pgste_set_key(ptep, pgste, entry, mm);
|
|
pgste = pgste_set_pte(ptep, pgste, entry);
|
|
pgste_set_unlock(ptep, pgste);
|
|
preempt_enable();
|
|
}
|
|
|
|
void ptep_set_notify(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
|
|
{
|
|
pgste_t pgste;
|
|
|
|
preempt_disable();
|
|
pgste = pgste_get_lock(ptep);
|
|
pgste_val(pgste) |= PGSTE_IN_BIT;
|
|
pgste_set_unlock(ptep, pgste);
|
|
preempt_enable();
|
|
}
|
|
|
|
/**
|
|
* ptep_force_prot - change access rights of a locked pte
|
|
* @mm: pointer to the process mm_struct
|
|
* @addr: virtual address in the guest address space
|
|
* @ptep: pointer to the page table entry
|
|
* @prot: indicates guest access rights: PROT_NONE, PROT_READ or PROT_WRITE
|
|
* @bit: pgste bit to set (e.g. for notification)
|
|
*
|
|
* Returns 0 if the access rights were changed and -EAGAIN if the current
|
|
* and requested access rights are incompatible.
|
|
*/
|
|
int ptep_force_prot(struct mm_struct *mm, unsigned long addr,
|
|
pte_t *ptep, int prot, unsigned long bit)
|
|
{
|
|
pte_t entry;
|
|
pgste_t pgste;
|
|
int pte_i, pte_p;
|
|
|
|
pgste = pgste_get_lock(ptep);
|
|
entry = *ptep;
|
|
/* Check pte entry after all locks have been acquired */
|
|
pte_i = pte_val(entry) & _PAGE_INVALID;
|
|
pte_p = pte_val(entry) & _PAGE_PROTECT;
|
|
if ((pte_i && (prot != PROT_NONE)) ||
|
|
(pte_p && (prot & PROT_WRITE))) {
|
|
pgste_set_unlock(ptep, pgste);
|
|
return -EAGAIN;
|
|
}
|
|
/* Change access rights and set pgste bit */
|
|
if (prot == PROT_NONE && !pte_i) {
|
|
ptep_flush_direct(mm, addr, ptep);
|
|
pgste = pgste_update_all(entry, pgste, mm);
|
|
pte_val(entry) |= _PAGE_INVALID;
|
|
}
|
|
if (prot == PROT_READ && !pte_p) {
|
|
ptep_flush_direct(mm, addr, ptep);
|
|
pte_val(entry) &= ~_PAGE_INVALID;
|
|
pte_val(entry) |= _PAGE_PROTECT;
|
|
}
|
|
pgste_val(pgste) |= bit;
|
|
pgste = pgste_set_pte(ptep, pgste, entry);
|
|
pgste_set_unlock(ptep, pgste);
|
|
return 0;
|
|
}
|
|
|
|
int ptep_shadow_pte(struct mm_struct *mm, unsigned long saddr,
|
|
pte_t *sptep, pte_t *tptep, pte_t pte)
|
|
{
|
|
pgste_t spgste, tpgste;
|
|
pte_t spte, tpte;
|
|
int rc = -EAGAIN;
|
|
|
|
if (!(pte_val(*tptep) & _PAGE_INVALID))
|
|
return 0; /* already shadowed */
|
|
spgste = pgste_get_lock(sptep);
|
|
spte = *sptep;
|
|
if (!(pte_val(spte) & _PAGE_INVALID) &&
|
|
!((pte_val(spte) & _PAGE_PROTECT) &&
|
|
!(pte_val(pte) & _PAGE_PROTECT))) {
|
|
pgste_val(spgste) |= PGSTE_VSIE_BIT;
|
|
tpgste = pgste_get_lock(tptep);
|
|
pte_val(tpte) = (pte_val(spte) & PAGE_MASK) |
|
|
(pte_val(pte) & _PAGE_PROTECT);
|
|
/* don't touch the storage key - it belongs to parent pgste */
|
|
tpgste = pgste_set_pte(tptep, tpgste, tpte);
|
|
pgste_set_unlock(tptep, tpgste);
|
|
rc = 1;
|
|
}
|
|
pgste_set_unlock(sptep, spgste);
|
|
return rc;
|
|
}
|
|
|
|
void ptep_unshadow_pte(struct mm_struct *mm, unsigned long saddr, pte_t *ptep)
|
|
{
|
|
pgste_t pgste;
|
|
|
|
pgste = pgste_get_lock(ptep);
|
|
/* notifier is called by the caller */
|
|
ptep_flush_direct(mm, saddr, ptep);
|
|
/* don't touch the storage key - it belongs to parent pgste */
|
|
pgste = pgste_set_pte(ptep, pgste, __pte(_PAGE_INVALID));
|
|
pgste_set_unlock(ptep, pgste);
|
|
}
|
|
|
|
static void ptep_zap_swap_entry(struct mm_struct *mm, swp_entry_t entry)
|
|
{
|
|
if (!non_swap_entry(entry))
|
|
dec_mm_counter(mm, MM_SWAPENTS);
|
|
else if (is_migration_entry(entry)) {
|
|
struct page *page = migration_entry_to_page(entry);
|
|
|
|
dec_mm_counter(mm, mm_counter(page));
|
|
}
|
|
free_swap_and_cache(entry);
|
|
}
|
|
|
|
void ptep_zap_unused(struct mm_struct *mm, unsigned long addr,
|
|
pte_t *ptep, int reset)
|
|
{
|
|
unsigned long pgstev;
|
|
pgste_t pgste;
|
|
pte_t pte;
|
|
|
|
/* Zap unused and logically-zero pages */
|
|
preempt_disable();
|
|
pgste = pgste_get_lock(ptep);
|
|
pgstev = pgste_val(pgste);
|
|
pte = *ptep;
|
|
if (!reset && pte_swap(pte) &&
|
|
((pgstev & _PGSTE_GPS_USAGE_MASK) == _PGSTE_GPS_USAGE_UNUSED ||
|
|
(pgstev & _PGSTE_GPS_ZERO))) {
|
|
ptep_zap_swap_entry(mm, pte_to_swp_entry(pte));
|
|
pte_clear(mm, addr, ptep);
|
|
}
|
|
if (reset)
|
|
pgste_val(pgste) &= ~_PGSTE_GPS_USAGE_MASK;
|
|
pgste_set_unlock(ptep, pgste);
|
|
preempt_enable();
|
|
}
|
|
|
|
void ptep_zap_key(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
|
|
{
|
|
unsigned long ptev;
|
|
pgste_t pgste;
|
|
|
|
/* Clear storage key */
|
|
preempt_disable();
|
|
pgste = pgste_get_lock(ptep);
|
|
pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT |
|
|
PGSTE_GR_BIT | PGSTE_GC_BIT);
|
|
ptev = pte_val(*ptep);
|
|
if (!(ptev & _PAGE_INVALID) && (ptev & _PAGE_WRITE))
|
|
page_set_storage_key(ptev & PAGE_MASK, PAGE_DEFAULT_KEY, 1);
|
|
pgste_set_unlock(ptep, pgste);
|
|
preempt_enable();
|
|
}
|
|
|
|
/*
|
|
* Test and reset if a guest page is dirty
|
|
*/
|
|
bool test_and_clear_guest_dirty(struct mm_struct *mm, unsigned long addr)
|
|
{
|
|
spinlock_t *ptl;
|
|
pgd_t *pgd;
|
|
pud_t *pud;
|
|
pmd_t *pmd;
|
|
pgste_t pgste;
|
|
pte_t *ptep;
|
|
pte_t pte;
|
|
bool dirty;
|
|
|
|
pgd = pgd_offset(mm, addr);
|
|
pud = pud_alloc(mm, pgd, addr);
|
|
if (!pud)
|
|
return false;
|
|
pmd = pmd_alloc(mm, pud, addr);
|
|
if (!pmd)
|
|
return false;
|
|
/* We can't run guests backed by huge pages, but userspace can
|
|
* still set them up and then try to migrate them without any
|
|
* migration support.
|
|
*/
|
|
if (pmd_large(*pmd))
|
|
return true;
|
|
|
|
ptep = pte_alloc_map_lock(mm, pmd, addr, &ptl);
|
|
if (unlikely(!ptep))
|
|
return false;
|
|
|
|
pgste = pgste_get_lock(ptep);
|
|
dirty = !!(pgste_val(pgste) & PGSTE_UC_BIT);
|
|
pgste_val(pgste) &= ~PGSTE_UC_BIT;
|
|
pte = *ptep;
|
|
if (dirty && (pte_val(pte) & _PAGE_PRESENT)) {
|
|
pgste = pgste_pte_notify(mm, addr, ptep, pgste);
|
|
__ptep_ipte(addr, ptep, IPTE_GLOBAL);
|
|
if (MACHINE_HAS_ESOP || !(pte_val(pte) & _PAGE_WRITE))
|
|
pte_val(pte) |= _PAGE_PROTECT;
|
|
else
|
|
pte_val(pte) |= _PAGE_INVALID;
|
|
*ptep = pte;
|
|
}
|
|
pgste_set_unlock(ptep, pgste);
|
|
|
|
spin_unlock(ptl);
|
|
return dirty;
|
|
}
|
|
EXPORT_SYMBOL_GPL(test_and_clear_guest_dirty);
|
|
|
|
int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
|
|
unsigned char key, bool nq)
|
|
{
|
|
unsigned long keyul;
|
|
spinlock_t *ptl;
|
|
pgste_t old, new;
|
|
pte_t *ptep;
|
|
|
|
ptep = get_locked_pte(mm, addr, &ptl);
|
|
if (unlikely(!ptep))
|
|
return -EFAULT;
|
|
|
|
new = old = pgste_get_lock(ptep);
|
|
pgste_val(new) &= ~(PGSTE_GR_BIT | PGSTE_GC_BIT |
|
|
PGSTE_ACC_BITS | PGSTE_FP_BIT);
|
|
keyul = (unsigned long) key;
|
|
pgste_val(new) |= (keyul & (_PAGE_CHANGED | _PAGE_REFERENCED)) << 48;
|
|
pgste_val(new) |= (keyul & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
|
|
if (!(pte_val(*ptep) & _PAGE_INVALID)) {
|
|
unsigned long address, bits, skey;
|
|
|
|
address = pte_val(*ptep) & PAGE_MASK;
|
|
skey = (unsigned long) page_get_storage_key(address);
|
|
bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
|
|
skey = key & (_PAGE_ACC_BITS | _PAGE_FP_BIT);
|
|
/* Set storage key ACC and FP */
|
|
page_set_storage_key(address, skey, !nq);
|
|
/* Merge host changed & referenced into pgste */
|
|
pgste_val(new) |= bits << 52;
|
|
}
|
|
/* changing the guest storage key is considered a change of the page */
|
|
if ((pgste_val(new) ^ pgste_val(old)) &
|
|
(PGSTE_ACC_BITS | PGSTE_FP_BIT | PGSTE_GR_BIT | PGSTE_GC_BIT))
|
|
pgste_val(new) |= PGSTE_UC_BIT;
|
|
|
|
pgste_set_unlock(ptep, new);
|
|
pte_unmap_unlock(ptep, ptl);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(set_guest_storage_key);
|
|
|
|
/**
|
|
* Conditionally set a guest storage key (handling csske).
|
|
* oldkey will be updated when either mr or mc is set and a pointer is given.
|
|
*
|
|
* Returns 0 if a guests storage key update wasn't necessary, 1 if the guest
|
|
* storage key was updated and -EFAULT on access errors.
|
|
*/
|
|
int cond_set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
|
|
unsigned char key, unsigned char *oldkey,
|
|
bool nq, bool mr, bool mc)
|
|
{
|
|
unsigned char tmp, mask = _PAGE_ACC_BITS | _PAGE_FP_BIT;
|
|
int rc;
|
|
|
|
/* we can drop the pgste lock between getting and setting the key */
|
|
if (mr | mc) {
|
|
rc = get_guest_storage_key(current->mm, addr, &tmp);
|
|
if (rc)
|
|
return rc;
|
|
if (oldkey)
|
|
*oldkey = tmp;
|
|
if (!mr)
|
|
mask |= _PAGE_REFERENCED;
|
|
if (!mc)
|
|
mask |= _PAGE_CHANGED;
|
|
if (!((tmp ^ key) & mask))
|
|
return 0;
|
|
}
|
|
rc = set_guest_storage_key(current->mm, addr, key, nq);
|
|
return rc < 0 ? rc : 1;
|
|
}
|
|
EXPORT_SYMBOL(cond_set_guest_storage_key);
|
|
|
|
/**
|
|
* Reset a guest reference bit (rrbe), returning the reference and changed bit.
|
|
*
|
|
* Returns < 0 in case of error, otherwise the cc to be reported to the guest.
|
|
*/
|
|
int reset_guest_reference_bit(struct mm_struct *mm, unsigned long addr)
|
|
{
|
|
spinlock_t *ptl;
|
|
pgste_t old, new;
|
|
pte_t *ptep;
|
|
int cc = 0;
|
|
|
|
ptep = get_locked_pte(mm, addr, &ptl);
|
|
if (unlikely(!ptep))
|
|
return -EFAULT;
|
|
|
|
new = old = pgste_get_lock(ptep);
|
|
/* Reset guest reference bit only */
|
|
pgste_val(new) &= ~PGSTE_GR_BIT;
|
|
|
|
if (!(pte_val(*ptep) & _PAGE_INVALID)) {
|
|
cc = page_reset_referenced(pte_val(*ptep) & PAGE_MASK);
|
|
/* Merge real referenced bit into host-set */
|
|
pgste_val(new) |= ((unsigned long) cc << 53) & PGSTE_HR_BIT;
|
|
}
|
|
/* Reflect guest's logical view, not physical */
|
|
cc |= (pgste_val(old) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 49;
|
|
/* Changing the guest storage key is considered a change of the page */
|
|
if ((pgste_val(new) ^ pgste_val(old)) & PGSTE_GR_BIT)
|
|
pgste_val(new) |= PGSTE_UC_BIT;
|
|
|
|
pgste_set_unlock(ptep, new);
|
|
pte_unmap_unlock(ptep, ptl);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(reset_guest_reference_bit);
|
|
|
|
int get_guest_storage_key(struct mm_struct *mm, unsigned long addr,
|
|
unsigned char *key)
|
|
{
|
|
spinlock_t *ptl;
|
|
pgste_t pgste;
|
|
pte_t *ptep;
|
|
|
|
ptep = get_locked_pte(mm, addr, &ptl);
|
|
if (unlikely(!ptep))
|
|
return -EFAULT;
|
|
|
|
pgste = pgste_get_lock(ptep);
|
|
*key = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56;
|
|
if (!(pte_val(*ptep) & _PAGE_INVALID))
|
|
*key = page_get_storage_key(pte_val(*ptep) & PAGE_MASK);
|
|
/* Reflect guest's logical view, not physical */
|
|
*key |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48;
|
|
pgste_set_unlock(ptep, pgste);
|
|
pte_unmap_unlock(ptep, ptl);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(get_guest_storage_key);
|
|
#endif
|